Synthesis and NOx sensing evaluation of hollow/porous La0.8Sr0.2MnO3 microspheres

To improve the nitric oxide (NO) gas reaction properties, we synthesized microspherical La0.8Sr0.2MnO3 (LSM) particles. We investigated the NO sensing properties of NOx sensors fabricated using electrodes based on... [ view full abstract ]

To improve the nitric oxide (NO) gas reaction properties, we synthesized microspherical La_0.8Sr_0.2MnO₃ (LSM) particles. We investigated the NO sensing properties of NOx sensors fabricated using electrodes based on hollow/porous LSM (hp-LSM) and solid sphere LSM particles. The hp-LSM particles were synthesized using a novel process combining spray pyrolysis with carbonization using citric acid. The resulting particles were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM), and their specific surface area was estimated using Brunauer–Emmett–Teller (BET) theory. The particle and pore size of the hp-LSM particles were estimated to be 1–3 mm and 100–500 nm, respectively, andtheir highest specific surface area was determined to be 6.8 m²/g. Sintered pellets made from hp-LSMparticles had a relative density of 68% and a broad pore size distribution between 100 and 1000 nm,estimated by the Archimedes method and mercury intrusion porosimetry measurements. The hp-LSMbasedgas sensing electrode exhibited a faster NO response/recovery time than the one based on solidLSM. This synthetic method is expected to be widely applicable to other materials, and hollow/porousparticles may be used for various applications such as gas sensors, batteries and chemical reactors.